GHF Archives - Thermtest Inc.

Measurement of through-plane effective thermal conductivity and contact resistance in PEM fuel cell diffusion media

Author(s): G. Karimi, P. Teertstra, X. Li

A study of the through-plane thermal conductivity of various gas diffusion layer materials (GDL) and the thermal contact resistance between the GDL and an electrolytic iron surface as a function ...

Keywords: electrolytic iron surface, experimental measurements, gas diffusion layer (GDL), GHF, Guarded heat flow meter, PEM fuel cell, proton exchange membrane, Thermal Conductivity, thermal contact resistance, Through-Plane Thermal Conductivity

Effect from a Variable U-Value in Adaptive Building Components with Controlled Internal Air Pressure

Author(s): Axel Berge, Bijan Adl-Zarrabi, Carl-Eric Hagentoft, Paula Wahlgrena

In an environment that experiences drastically changing temperatures it is potentially more energy efficient to use insulative walls that can change their apparent thermal conductivities. This paper suggests a nano-porous ...

Keywords: building energy, energy balance, GHF, Guarded heat flow meter, heating, insulation, Nanoporous materials, Thermal Conductivity, U-values

Design, Assembly and Commisioning of a Test Apparatus for Characterizing Thermal Interface Materials

Author(s): I. Savija, J. R. Culham, M. M. Yovanovich, P. Teertstra

Thermal interface materials (TIMs) are often used in electronic and microelectronic applications. It can be difficult to determine their characteristics once they are in-situ because it is hard to account ...

Keywords: Contact resistance, electronics, GHF, in-situ thickness measurement, metallic foils, phase change materials, Polymeric materials, test apparatus, Thermal Conductivity, thermal interface materials

Thermal Conductivity and Contact Resistance Measurements for Adhesives

Author(s): Peter Teertstra

Thermal adhesives that contain large proportions of high thermal conductivity filler materials are extremely useful in electronics and manufacturing. Due to the importance of these fillers it is crucial to ...

Keywords: adhesive, electronics, filler materials, GHF, Guarded heat flow meter, Heat Transfer, Microelectronics, Thermal Conductivity, thermal paste

Measurements of the Thermal Conductivity of Lithium Polymer Battery Composite Cathodes

Author(s): James W. Evans, Li Song

Thermal management is extremely important for large size batteries, however, inaccurate values have been used in the past for modeling. This paper investigates the thermal conductivity of the composite cathodes. ...

Keywords: composite cathodes, GHF, Guarded heat flow meter, lithium polymer electrolytes, lithium polymer ion batteries, thermal resistivity, TiS2, V6O13

Direct measurement of through-plane thermal conductivity and contact resistance in fuel cell materials

Author(s): M. M. Mench, Manish Khandelwal

The through-plane thermal conductivity of many components of a fuel cell, dry Nafion®, various diffusion medias and catalyst layers are studied. The thermal contact resistance between the diffusion media and ...

Keywords: catalyst layer, diffusion media, dry nafion, Fuel cells, GHF, Guarded heat flow meter, Nafion membrane, polymers, thermal contact resistance, Through-Plane Thermal Conductivity, Toray carbon fiber paper

Improving speed and precision of using guarded heat flow technique to measure thin specimens

Author(s): Dante J. Dorantes-Gonzalez, J. Liu, Q. C. Nie, Y. N. Li, Z. Chen

This paper introduces a compensation algorithm and a different-layers calibration method that will improve the temperature measurement speed and thermal resistance elimination of a guarded heat flow meter instrument. Without ...

Keywords: compensation algorithm, Contact resistance, different-layers calibration, GHF, Guarded heat flow meter, Steady state, Thermal Conductivity, thermal contact resistance, Thermal Resistance

Estimation of the thermal properties of hardened cement paste on the basis of guarded heat flow meter measurements

Author(s): Donald E. Macphee, Mohammed S. Imbabi, Seyoon Yoon

A new analysis method based on the guarded heat flow meter apparatus is proposed to measure the thermal properties of cement-based pastes in a hydrated form. In a steady state, ...

Keywords: Cement, concrete, Contact resistance, GHF, Guarded Heat Flow meter Method, specific heat capacity, Steady state, Thermal Conductivity, Thermal Diffusivity, Transient

Intercomparison of Measurements of the Thermophysical Properties of Polymethyl Methacrylate

Author(s): S. Rudtsch, U. Hammerschmidt

The variability within the results presented from the guarded hot-plate (GHP) and guarded heat-flow meter (GHF) methods was determined. Multiple thermal properties of polymethyl methacrylate (PMMA) were analyzed to compare ...

Keywords: Differential scanning calorimetry (DSC), GHF, Guarded heat flow meter, guarded hot plate (GHP), needle probe technique, Polymethyl methacrylate (PMMA), specific heat capacity, Thermal Conductivity, Thermal Diffusivity, Transient hot-strip (THS), Transient Plane Source Technique

Thermal conductivity of catalyst layer of polymer electrolyte membrane fuel cells: Part 1 – Experimental study

Author(s): Jürgen Stumper, Madhu S. Saha, Majid Bahrami, Mickey Tam, Mohammad Ahadi

In this paper, a new method is proposed for measuring the through plane thermal conductivity of two catalyst layers of different thicknesses by the guarded heat flow meter (GHF) method, ...

Keywords: catalyst layer, GHF, Guarded heat flow meter, membrane fuel cell, Polymer electrolyte, Thermal Conductivity, thermal contact resistance, Through-Plane Thermal Conductivity, TPS, Transient Plane Source

Keyword: GHF